Effects of acute or chronic administration of low doses of a dopamine agonist on drinking and locomotor activity in the rat.
Low doses of piribedil (0.25-5.0 mg/kg) administered acutely produced reliable decrements in locomotor activity in thirsty and non-thirsty animals, the greatest effect occurring at the highest dose. A sequence of ten daily injections of piribedil produced indications of the development of tolerance, at the two highest doses (2.5 and 5.0 mg/kg) in thirsty animals. The smallest doses used, given either acutely or chronically, produced a weak enhancement of drinking behaviour within the first 15 min of a drinking test, as shown by a reduction in latency to drink and an increase in the amount of water consumption. Tolerance did develop with respect to drinking behaviour; animals treated chronically with piribedil displayed higher levels of drinking at several dose levels when compared with acutely treated subjects. The tolerance displayed at the two highest doses could have a close affinity with that shown with regard to locomotor activity.
D000818:Animals; D004327:Drinking Behavior / Q000187:drug effects*; D004361:Drug Tolerance; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D010879:Piperazines / Q000494:pharmacology*; D010891:Piribedil / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D013997:Time Factors; D014868:Water Deprivation / Q000502:physiology
D010879:Piperazines; D010891:Piribedil